Mr. Chevalier has been diagnosed with Horner syndrome, which is caused by dysfunction of the sympathetic neurons in the superior cervical ganglion that innervate structures of the head, face, and neck. What symptoms is Mr. Chevalier likely to face due to his disease? Explain.

Verified step by step guidance

1. Understand that Horner syndrome is a result of disruption in the sympathetic nervous system, specifically affecting the superior cervical ganglion.
2. Recognize that the sympathetic nervous system is responsible for the 'fight or flight' response, which includes pupil dilation, eyelid elevation, and sweating.
3. Identify that due to the dysfunction in the sympathetic neurons, Mr. Chevalier may experience ptosis (drooping of the upper eyelid) because the muscles that elevate the eyelid are not receiving proper sympathetic stimulation.
4. Consider that miosis (constricted pupil) may occur because the dilator muscle of the pupil is not being activated by the sympathetic nervous system.
5. Acknowledge that anhidrosis (lack of sweating) on the affected side of the face may also be a symptom, as the sweat glands are not receiving sympathetic signals.

Key Concepts

Horner Syndrome

Horner syndrome is a neurological condition resulting from disruption of sympathetic nerve pathways, particularly affecting the eye and surrounding structures. It is characterized by a triad of symptoms: ptosis (drooping of the upper eyelid), miosis (constricted pupil), and anhidrosis (lack of sweating) on the affected side of the face. Understanding this syndrome is crucial for identifying the specific symptoms Mr. Chevalier may experience.

Sympathetic Nervous System

The sympathetic nervous system is part of the autonomic nervous system responsible for the body's 'fight or flight' response. It regulates involuntary functions such as heart rate, blood pressure, and sweating. Dysfunction in this system, particularly in the superior cervical ganglion, can lead to the symptoms seen in Horner syndrome, highlighting the importance of sympathetic pathways in facial and ocular function.

Superior Cervical Ganglion

The superior cervical ganglion is the largest of the sympathetic ganglia and is located in the neck. It plays a critical role in innervating structures in the head and neck, including the eyes, salivary glands, and sweat glands. Damage or dysfunction in this ganglion can lead to the hallmark symptoms of Horner syndrome, making it essential to understand its function and location in relation to Mr. Chevalier's condition.